Flowserve NMD - Manual (Page 19)

NMD, NMAD USER INSTRUCTIONS ENGLISH 71576436 - 11/09
Page 19 of 40
Without foot valve:
Priming may be accomplished by means of venting
system.
Foot valves are not recommended when
the pumped liquid has suspended solid particles.
They may lodge between foot valve seat and
shutter.
5.4 Starting the pump
5.4.1 Bring controls and preparation before the
first starting and after each service call
Necessarily:
a) Check the tightening of the different plugs.
b) Check that the gland lightly tightens the packing
rings.
c) Risk of seal ring overheating.
d) Check the direction of rotation of the motor.
Refer to the rotation arrow of the pump.
e) Install all protection systems and more
particularly the coupling guard [7450] and the
shield grid [9331] of the bearing.
f) Open all suction valves (if existing).
g) Close the outlet valve and the bypass valve.
h) Ensure inlet pipe and pump casing are
completely full of liquid.
5.4.2 First pump start-up
Suction valves must be fully open
when pump is running. Never run the pump dry, it
will cause damage.
a) Start motor and check outlet pressure.
b) If pressure is satisfactory, slowly OPEN outlet
valve.
c) Do not run the pump with the outlet valve closed
for a period longer than 30 seconds.
d) If NO pressure, or LOW pressure, STOP the
pump. Refer to faultfinding chart for fault
diagnosis.
The pump should run smoothly and without
vibration.
The pump must never run at a capacity less than
10 % (for 102-122-152-202 NMD or NMAD and for
252 NMD) of the capacity at the best efficiency
point.
Never remove a plug when the pump is
running.
5.5 Running the pump
5.5.1 Venting the pump
Vent the pump to enable all trapped air to
escape taking due care with hot or hazardous
liquids.
Under normal operating conditions, after the pump
has been fully primed and vented, it should be
unnecessary to re-vent the pump.
5.5.2 Pump fitted with a stuffing box
If the pump has a packed gland there must be some
leakage from the gland. Gland nuts should initially
be finger tight only. Leakage should take place soon
after the stuffing box is pressurized. If no leakage
takes place the packing will begin to overheat. If
overheating takes place the pump should be
stopped and allowed to cool before being restarted.
When the pump is restarted it should be checked to
ensure leakage is taking place at the packed gland.
When adjusting an operating stuffing box
(shield grids removed for this operation) the operator
must be very careful. Safety gloves are compulsory
and loose clothes are not allowed (above all to the
arms) to avoid being caught by the pump shaft.
The pump should be run for ten minutes with steady
leakage and the gland nuts tightened by 10 degrees
at a time until leakage is reduced to an acceptable
level. The temperature of the gland should be
checked after each round of tightening. If the
temperature starts to climb rapidly then back off the
gland nuts until the temperature drops down. Wait
for the temperature to stabilize before tightening
again. The leakage must not be reduced below a
rate of 20 drops per minute. Bedding in of the
packing may take several hours.